A regrettable consequence of the human aging process is the gradual loss of photoreceptors in the retina of the eye. Also, a number of pathologic processes affect the structures of the eye and degrade their ability to transmit or detect light. These processes reduce the useful vision of affected persons, and cannot be corrected by or enhanced with typical refracting lenses found in spectacles.
Contemporary solutions involve the enlargement of content for affected persons. This involves magnifying lenses that attach to spectacles, handheld magnifying instruments, and projection screens that enlarge content. Additionally, for personal computers, a small number of software products will increase the size of on-screen content. Continuing efforts are being made to enhance the functioning of persons of low visual acuity, particularly with respect to the increasing presence of personal computing in daily life.